There are two kinds of air conditioners, window air conditioner and split-type air conditioner. A window air conditioner has small size and lower price, but it makes louder noise indoors. Compared with conventional window air conditioner, a split-type air conditioner generates lower noise, but it has its disadvantages as follows: 1. Bulk in volume, high production cost, inconvenient for transportation and installation; 2. The pipes of the indoor unit and outdoor unit are connected by coupler connection, the consequent lack of tightness causes refrigerant leakage, which increases the refrigerant consumption, causes inconvenience for use, and is destructive to ozonosphere; 3. The outdoor fresh air can not be supplied to indoors, which is harmful to human body, and easily to cause "air conditioner symptom"; 4. There is risk for the outdoor unit installed on wall of high buildings to fall down and hurt passengers due to corrosion and looseness of the fixing frame.